Castor oil is a unique triglyceride. It is derived from Ricinus communis L. The castor plant grows wild in many subtropical and tropical areas Today Brazil, China and India provide over 90% of the oil. Castor oil contains a large content of hydroxy containing compounds that are unsaturated.
Castor Oil is a clear, viscous, fight colored fluid that is nondrying and quite stable. The Purity of Castor Oil occurs with remarkable uniformity. Regardless of country of origin, or season it is grown, the composition and chemical properties remain within a very narrow range. Castor Oil has broad compatibility with oils, waxes, natural resins, and gums.
Another unique aspect of castor oil is the high level of ricinoleic acid in the molecule. Castor oil contains 89% of the acid, which conforms to the following structure; 
When hydrogenated the double bond is lost giving hydrogenated ricinoleic, or 12-hydroxy stearic acid. 
When the acids derived from castor (ricinoleic acid) are reacted with alcohols having 6 to 22 carbon atoms the resulting esters are also suitable candidates for phosphation. wherein R is CH3—(CH2)n— and n is an integer ranging from 5 to 21.
When the acids derived from hydrogenated castor (12-hydroxy-stearic acid) are reacted with alcohols having 6 to 22 carbon atoms the resulting esters are also suitable candidates for phosphation. wherein R is CH3—(CH2)n— and n is an integer ranging from 5 to 21.